P-type IIIA group metal oxide semiconductor film and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor materials. The invention provides a p-type group IIIA metal oxide semiconductor film and a preparation method thereof, and the preparation method employs an MOCVD method, employs a group IIIA metal source, an oxygen source, a group VIA non-oxygen precursor and a p-type doped precursor as raw materials, and carries out a deposition reaction to obtain the p-type group IIIA metal oxide semiconductor film. Two specific impurities are used in the MOCVD deposition process to form co-doping on the group IIIA metal oxide, the p-type group IIIA metal oxide semiconductor film is directly obtained, the energy level of acceptor and donor doping is effectively reduced, the number of carriers generated by each doping is increased, and the performance of the semiconductor film is improved. And the preparation method is convenient for realizing epitaxial growth on the IIIA group metal oxide substrate to form a single-layer or multi-layer structure, and is simple and convenient to operate, relatively low in cost and suitable for large-scale preparation.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor materials, and relates to a p-type group IIIA metal oxide semiconductor thin film and a preparation method thereof. Background Art

[0002] Compact high-power systems, such as high-efficiency power switches, radio frequency devices, and converters capable of handling high power densities, require the use of wide bandgap (WBG) and ultra-wide bandgap (UWBG) semiconductors and devices with a vertical structure. To achieve high efficiency, such devices need to utilize the structural design of p-n junctions and selective area doping.

[0003] In this regard, taking gallium nitride (GaN) as an example, although it can currently achieve sufficient p-type doping or n-type doping respectively, there are some problems in forming highly reliable and high-performance selective lateral area p-n junctions, which limits its application in fields such as vertical power transistors. Only by first achieving selective area doping in GaN and obtaining materials of sufficient quality to form defect-free p-n junctions can the advantages of vertical power devices be fully utilized. At the same time, although GaN and its alloys still have certain room for development, if higher requirements in terms of power handling ability and cost are to be met and the next level of improvement is to be achieved, new ultra-wide bandgap semiconductor materials need to be further developed, such as gallium oxide (Ga 2 O 3 ), cubic boron nitride (c-BN), and diamond, etc.

[0004] Among them, gallium oxide has a bandgap of 4.9 eV and is a promising ultra-wide bandgap semiconductor. The Baliga figure of merit (BFOM) is used to measure the power loss of a semiconductor. The higher the BFOM value, the lower the loss, and it is often used to evaluate the applicability of semiconductor materials in the field of power electronics. Among the materials studied in the current literature, the theoretical breakdown voltage of Ga 2 O 3 reaches 8 MV / cm, and its BFOM value is 4 times that of GaN and 14 times that of 4H-SiC. Therefore, compared with 4H-SiC and GaN, the resistance loss and switching loss of Ga 2 O 3 are expected to be lower. Moreover, due to its relatively large dielectric constant, at the same doping level, the critical field strength of Ga 2 O 3 is larger than that of silicon. Therefore, at the same doping level, the drift region thickness of Ga 2 O 3 is only 1 / 27 of that of silicon, which enables Ga 2 O 3 to have a higher power density capacity. The Johnson figure of merit, which measures the high-frequency operation applicability of semiconductor materials, for Ga 2 O3 It is 6 times and 15 times larger than GaN and SiC respectively, which also makes it quite attractive for higher power RF applications. Therefore, Ga 2 O 3 is a promising material candidate for the next generation of power device technologies.

[0005] However, although some progress has been made in n-type doping of these new ultra-wide bandgap semiconductors, there are still many doping problems to be solved. For example, the n-type conductivity of Ga 2 O 3 can be easily adjusted by several orders of magnitude, but in order to further expand its application range, realizing p-type Ga 2 O 3 is the key. Although theoretically, p-type doping can be achieved by replacing Ga sites with group IIB (Zn) elements or O sites with group VA elements (N, P, and As), there are still very limited reports on successful shallow acceptor doping and hole conduction in Ga 2 O 3 at present.

[0006] Therefore, it is still necessary to study the scheme for forming p-type ultra-wide bandgap semiconductor materials to support the application and development of high-power performance electronic components. SUMMARY OF THE INVENTION

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a p-type group IIIA metal oxide semiconductor thin film and a preparation method thereof. The preparation method uses MOCVD (Metal-Organic Chemical Vapor Deposition) method, and uses a group IIIA metal source, an oxygen source, a group VIA non-oxygen precursor, and a p-type doping precursor as raw materials to carry out a deposition reaction to obtain a p-type group IIIA metal oxide semiconductor thin film. By using two specific impurities to co-dope the group IIIA metal oxide during the MOCVD deposition process, a p-type group IIIA metal oxide semiconductor thin film is directly obtained, effectively reducing the energy levels of acceptor and donor doping, increasing the number of carriers generated by each doping, and the preparation method is convenient for realizing epitaxial growth on a group IIIA metal oxide substrate to form a single-layer or multi-layer structure, with simple and convenient operation, low cost, and suitable for large-scale preparation.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. Using the MOCVD method, with a group IIIA metal source, an oxygen source, a group VIA non-oxygen precursor, and a p-type doping precursor as raw materials, a deposition reaction is carried out to obtain a p-type group IIIA metal oxide semiconductor thin film.

[0010] In the preparation method of the present invention, by using two specific impurities to co-dope the group IIIA metal oxide during the MOCVD deposition process, a p-type group IIIA metal oxide semiconductor thin film is directly obtained, effectively reducing the energy levels of acceptor and donor doping, increasing the number of carriers generated by each doping, reducing the resistivity of the thin film, and not greatly affecting the bandgap of the thin film material itself. At the same time, the preparation method is convenient for realizing epitaxial growth on a group IIIA metal oxide substrate to form a single-layer or multi-layer structure, is simple and convenient to operate, has a low cost, and is suitable for large-scale preparation.

[0011] The following are preferred technical solutions of the present invention, but not limitations to the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, the group IIIA element in the group IIIA metal source includes gallium and / or aluminum.

[0013] Preferably, the group IIIA metal source includes an organometallic compound containing a group IIIA element.

[0014] Preferably, the organometallic compound containing a group IIIA metal includes at least one of trimethylgallium, triethylgallium, trimethylaluminum, or triethylaluminum.

[0015] As a preferred technical solution of the present invention, the oxygen source includes oxygen (O 2 ), water (H 2 O), or nitrous oxide (N 2 O) or at least one of them.

[0016] Preferably, the molar ratio of the oxygen element in the oxygen source to the group IIIA element in the group IIIA metal source is (100 - 500):1, such as 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, or 500:1, etc.

[0017] Preferably, when the oxygen source contains oxygen, the molar ratio of the oxygen element in the oxygen to the Group IIIA element in the Group IIIA metal source is (350 - 500):1; when the oxygen source contains nitrous oxide, the molar ratio of the oxygen element in the nitrous oxide to the Group IIIA element in the Group IIIA metal source is (200 - 350):1; when the oxygen source contains water, the molar ratio of the oxygen element in the water to the Group IIIA element in the Group IIIA metal source is (100 - 200):1.

[0018] As a preferred technical solution of the present invention, the Group VIA element in the Group VIA non-oxygen precursor includes at least one of sulfur, selenium, or tellurium.

[0019] Preferably, the Group VIA non-oxygen precursor includes an organic compound containing a Group VIA element.

[0020] Preferably, the organic compound containing a Group VIA element includes at least one of thiol, dimethyl sulfide, diethyl sulfide, selenol, dimethyl selenide, diethyl selenide, tellurol, dimethyl telluride, or diethyl telluride.

[0021] Preferably, the molar ratio of the Group IIIA element in the Group IIIA metal source to the Group VIA element in the Group VIA non-oxygen precursor is (3 - 30):1, such as 3:1, 3.3:1, 3.5:1, 3.8:1, 4:1, 4.2:1, 4.5:1, 4.8:1, 5:1, 8:1, 10:1, 13:1, 15:1, 18:1, 20:1, 23:1, 25:1, 28:1, or 30:1, etc., but is not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0022] It should be noted that the incorporation amount of the Group VIA element in the Group VIA non-oxygen precursor will affect the carrier concentration of the obtained p-type Group IIIA metal oxide semiconductor thin film. When the molar ratio of the Group IIIA element in the Group IIIA metal source to the Group VIA element in the Group VIA non-oxygen precursor is 30:1, it is still necessary to ensure that the carrier concentration of the obtained p-type Group IIIA metal oxide semiconductor thin film ≥ 1.0×10 13 cm -3 .

[0023] As a preferred technical solution of the present invention, the doping element contained in the p-type doping precursor includes at least one of lithium, beryllium, or magnesium.

[0024] Preferably, the p-type doping precursor includes an organometallic compound containing a doping element.

[0025] Preferably, the organometallic compound containing a doping element includes at least one of lithium acetylacetonate, beryllium acetylacetonate, magnesium bis(cyclopentadienyl), or diethylmagnesium.

[0026] Preferably, the molar ratio of the doping element in the p-type doping precursor to the Group IIIA element in the Group IIIA metal source is (0 to 10):1000, such as 0:1000 (i.e., without using the p-type doping precursor), 0.1:1000, 0.2:1000, 0.3:1000, 0.4:1000, 0.5:1000, 0.6:1000, 0.7:1000, 0.8:1000, 0.9:1000, 1:1000, 2:1000, 3:1000, 4:1000, 5:1000, 6:1000, 7:1000, 8:1000, 9:1000 or 10:1000, etc. Preferably, it is (0.001 to 8):1000, but is not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0027] It should be noted that when the molar ratio of the doping element in the p-type doping precursor to the Group IIIA element in the Group IIIA metal source is 0:1000, the obtained p-type Group IIIA metal oxide semiconductor thin film corresponds to the lowest hole concentration (≥1.0×10 13 cm -3 ), and when the molar ratio is 10:1000, it corresponds to the highest hole concentration (≤5×10 20 cm -3 ).

[0028] As a preferred technical solution of the present invention, the Group IIIA metal source, oxygen source, Group VIA non-oxygen precursor, and p-type doping precursor are transported by a carrier gas.

[0029] Preferably, the carrier gas includes nitrogen and / or argon.

[0030] As a preferred technical solution of the present invention, the temperature of the deposition reaction is 500 to 1000 °C, such as 500 °C, 600 °C, 700 °C, 800 °C, 900 °C or 1000 °C, etc. But is not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0031] Preferably, the pressure of the deposition reaction is 30 to 100 mbar, such as 30 mbar, 40 mbar, 50 mbar, 60 mbar, 70 mbar, 80 mbar, 90 mbar or 100 mbar, etc. But is not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0032] As a preferred technical solution of the present invention, the deposition reaction is carried out on a substrate.

[0033] Preferably, the material of the substrate includes group IIIA metal oxides to achieve epitaxial deposition. Further, the group IIIA element in the material of the substrate is the same as the group IIIA element in the p-type group IIIA metal oxide semiconductor thin film.

[0034] Preferably, the group IIIA metal oxide includes at least one of gallium oxide, aluminum oxide or aluminum gallium oxide.

[0035] Preferably, the group IIIA metal oxide is n-type doped.

[0036] As a preferred technical solution of the present invention, after the deposition reaction is completed, annealing is carried out to obtain the p-type group IIIA metal oxide semiconductor thin film.

[0037] Preferably, the annealing temperature is 600-1200 °C, such as 600 °C, 650 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, 950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C or 1200 °C, etc., and the time is 0.5-5 min, such as 0.5 min, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min or 5 min, etc., but not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0038] Preferably, the thickness of the p-type group IIIA metal oxide semiconductor thin film is 50 nm-10 μm, such as 50 nm, 80 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm, etc., but not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0039] In a second aspect, the present invention provides a p-type group IIIA metal oxide semiconductor thin film obtained by the preparation method according to the first aspect.

[0040] As a preferred technical solution of the present invention, the carrier concentration of the p-type group IIIA metal oxide semiconductor thin film is 1.0×10 13 ~5×10 20 cm -3 , such as 1.0×10 13 cm -3 , 5×10 13 cm -3 , 8×10 13 cm -3, 1×10 14 cm -3 , 5×10 14 cm -3 , 8×10 14 cm -3 , 1×10 15 cm -3 , 5×10 15 cm -3 , 8×10 15 cm -3 , 1×10 16 cm -3 , 5×10 16 cm -3 , 8×10 16 cm -3 , 1×10 17 cm -3 , 5×10 17 cm -3 , 8×10 17 cm -3 , 1×10 18 cm -3 , 5×10 18 cm -3 , 8×10 18 cm -3 , 1×10 19 cm -3 , 5×10 19 cm -3 , 8×10 19 cm -3 , 1×10 20 cm -3 or 5×10 20 cm -3 etc.; resistivity ≤ 2500 Ω·cm, such as 2500 Ω·cm, 2400 Ω·cm, 2300 Ω·cm, 2200 Ω·cm, 2100 Ω·cm, 2000 Ω·cm, 1800 Ω·cm, 1600 Ω·cm, 1400 Ω·cm, 1200 Ω·cm, 1000 Ω·cm, 800 Ω·cm, 500 Ω·cm, 300 Ω·cm, 100 Ω·cm, 80 Ω·cm, 60 Ω·cm, 40 Ω·cm, 20 Ω·cm, 10 Ω·cm, 8 Ω·cm or 5 Ω·cm etc., more preferably ≤ 2000 Ω·cm, but not limited to the listed values, and other unlisted values within the above numerical range are equally applicable.

[0041] In a third aspect, the present invention provides a use of the p-type group IIIA metal oxide semiconductor thin film described in the second aspect, and the use includes being used in power devices, such as PN junction diodes, avalanche breakdown diodes, field effect transistors, etc.

[0042] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0043] In the preparation method of the present invention, two specific impurities are used for co-doping the group IIIA metal oxide during the MOCVD deposition process to directly obtain a p-type group IIIA metal oxide semiconductor thin film, effectively reducing the energy levels of acceptor and donor doping, increasing the number of carriers generated by each doping, reducing the resistivity of the thin film, and not greatly affecting the bandgap of the thin film material itself. At the same time, the preparation method is convenient for epitaxial growth on a group IIIA metal oxide substrate to form a single-layer or multi-layer structure, is simple and convenient to operate, has a low cost, and is suitable for large-scale preparation. Description of the Drawings

[0044] Figure 1 It is a resistivity test chart of the p-type group IIIA metal oxide semiconductor thin film obtained in Example 1. Detailed Embodiments

[0045] The technical solutions of the present invention will be further described below through specific embodiments.

[0046] Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0047] Example 1

[0048] This example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film, and the preparation method includes:

[0049] (1) Place the cleaned iron-doped semi-insulating gallium oxide wafer as the substrate into the chemical vapor deposition reaction chamber. After evacuating the reaction chamber, while introducing nitrogen and oxygen, heat it at 1000 °C for 10 min to remove surface contaminants.

[0050] (2) Next, cool down to 800 °C and maintain it, and reduce the pressure to 30 mbar and maintain it. Introduce 9.6×10 -5 mol / min of triethylgallium, introduce 0.25 mol / min of O 2 , introduce 3.2×10 -5 mol / min of diethylselenium, introduce 1×10 -8Magnesium bis(cyclopentadienyl) at a rate of

[0051] (3) After cooling, the grown wafer was taken out from the chemical vapor deposition reaction chamber.

[0052] Example 2

[0053] This example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, diethyl selenide was replaced with diethyl telluride, and its dosage was adjusted from 3.2×10 -5 mol / min to 3.2×10 -4 mol / min, so that the molar ratio of Te to Ga atoms was 1:3. Except for the above, other conditions were exactly the same as those in Example 1.

[0054] Example 3

[0055] This example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, diethyl selenide was replaced with diethyl telluride, and its dosage was adjusted from 3.2×10 -5 mol / min to 1.92×10 - 4 mol / min, so that the molar ratio of Te to Ga atoms was 1:5. Except for the above, other conditions were exactly the same as those in Example 1.

[0056] Example 4

[0057] This example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, diethyl selenide was replaced with diethyl telluride, and its dosage was adjusted from 3.2×10 -5 mol / min to 5.33×10 - 5 mol / min, so that the molar ratio of Te to Ga atoms was 1:18. Except for the above, other conditions were exactly the same as those in Example 1.

[0058] Example 5

[0059] This example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, the dosage of diethyl selenide was adjusted from 3.2×10 -5 mol / min to 3.2×10 -5mol / min, such that the molar ratio of Te to Ga atoms is 1:30. Except for this, other conditions are exactly the same as those in Example 1.

[0060] Comparative Example 1

[0061] This comparative example provides a method for preparing a group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, the dosage of diethyl selenide is adjusted from 3.2×10 -5 mol / min to 0 mol / min, that is, diethyl selenide is not used. Except for this, other conditions are exactly the same as those in Example 1.

[0062] Comparative Example 2

[0063] This comparative example provides a method for preparing a p-type group IIIA metal oxide semiconductor thin film. In step (2) of the preparation method, the dosage of magnesium bis(cyclopentadienyl) is adjusted from 1×10 -8 mol / min to 0 mol / min, that is, magnesium bis(cyclopentadienyl) is not used. Except for this, other conditions are exactly the same as those in Example 1.

[0064] Characterization and testing:

[0065] Deposit a metal contact layer, such as nickel and / or gold (exemplarily, the thickness of nickel is 20 nm and the thickness of gold is 80 nm), on the p-type group IIIA metal oxide semiconductor thin films obtained in the examples and comparative examples, and perform rapid thermal annealing in a nitrogen atmosphere at 470 °C; and evaluate the conduction type and electrical properties of p-type gallium oxide through the Van der Pauw method and Hall testing (the Hall magnetic field strength in this article is 1.5 T).

[0066] Figure 1 Fig. is the resistivity result diagram of the p-type group IIIA metal oxide semiconductor thin film obtained in Example 1. It can be seen from the figure that its resistivity at room temperature (from 288.15 K to 308.15 K) is 30 Ω·cm, and its change trend conforms to the trend of the resistivity of semiconductor materials changing with temperature.

[0067] Other data are listed in Table 1.

[0068] Table 1

[0069] Group Resistivity at 298.15K (Ω·cm) <![CDATA[Mobility (cm 2 / V·s)]]> <![CDATA[Carrier concentration (cm -3 )]]> Example 1 32.86 0.6 <![CDATA[8×10 17 <!-- 5 -->]]> Example 2 9.8 0.2 <![CDATA[5×10 18 > Example 3 34.07 0.55 <![CDATA[8×10 17 > Example 4 908.2 1.51 <![CDATA[4.55×10 16 > Example 5 2064 5.29 <![CDATA[5.88×10 15 > Comparative Example 1 <![CDATA[>2×10 5 > Unmeasurable Unmeasurable Comparative Example 2 5865 / <![CDATA[3.1×10 12 cm -3 ~5.7×10 14 cm -3 >

[0070] It can be seen from Table 1 that:

[0071] In Example 1, Se (Group VIA) and Mg (p-type dopant) were co-doped into the gallium oxide system by MOCVD method, and a 1.5-μm-thick p-type semiconductor thin film was deposited under the conditions of 800 °C and 30 mbar. Its room-temperature resistivity is 32.86 Ω·cm, and the carrier concentration reaches 8×10 17 cm-3 , the significant improvement of hole conductivity by the double doping strategy was verified.

[0072] As can be seen from Examples 2 - 5, the amount of Group VI A non - oxygen element incorporated determines the upper limit of carrier concentration and further the level of resistivity. From the comparison between Examples 3 and 6, when the doping ratio of Te to Ga increases from 1:30 to 1:3, the carrier concentration increases from 5.88×10 15 cm -3 to 5×10 18 cm -3 , and the resistivity drops by three orders of magnitude. While Comparative Example 1 that completely abandons Group VI A doping cannot form effective conductivity (resistivity > 2×10 5 Ω·cm), directly confirming the key role of the donor compensation effect of Group VI A elements in p - type conductivity.

[0073] The test results of Comparative Example 2 clearly show that single doping with only Group VI A non - oxygen elements (such as selenium or tellurium) cannot form sufficient p - type effective carriers. In this comparative example, no p - type dopant (magnesium) was introduced, and only Group VI A selenium element was introduced through diethyl selenide. The results show that the upper limit of carrier concentration is only 5.7×10 14 cm -3 , and the resistivity is as high as 5865Ω·cm, far inferior to Example 1 (when magnesium - doped, the carrier concentration is 8×10 17 cm -3 , and the resistivity is 32.86Ω·cm).

[0074] This phenomenon can be explained by semiconductor energy band theory and defect chemistry mechanism: when Group VI A elements (such as Se) replace oxygen sites (O 2- ), they provide donor electrons (Se 4+ →O 2- forming a +2 charge state), but simple donor doping will increase n - type conductivity and cannot directly induce the formation of holes. In the double - doping system of the present invention, p - type dopants (such as Mg 2+ ) replace Al 3+ / Ga 3+The site forms an acceptor state (generating a -1 charge state), which forms a charge compensation effect with group-VIA donor doping, thereby suppressing the donor-acceptor self-compensation phenomenon and simultaneously reducing the ionization energy of magnesium acceptors. For example, in a IIIA group metal oxide semiconductor doped solely with Mg theoretically, the depth of the Mg acceptor energy level is approximately 1.1 eV, while in the Se / Mg co-doping system, the composite defect center formed by the Se donor energy level (shallow energy level) and Mg acceptors can reduce the ionization energy to below 0.8 eV, significantly improving the room-temperature hole ionization efficiency. The low carrier concentration in Comparative Example 2 is precisely due to the lack of the synergistic effect of acceptor doping. Single group-VIA donor doping not only fails to provide a hole conduction channel but may also exacerbate carrier scattering due to excessive free electrons, leading to deteriorated resistivity. Therefore, the co-doping of group-VIA non-oxygen elements and p-type dopants is the key innovation point for breaking through the conductivity bottleneck of p-type IIIA group metal oxide semiconductors.

[0075] In summary, the preparation method described in the present invention directly obtains a p-type IIIA group metal oxide semiconductor thin film by using two specific impurities for co-doping of IIIA group metal oxides during the MOCVD deposition process, effectively reducing the energy levels of acceptor and donor doping, increasing the number of carriers generated by each doping, reducing the resistivity of the thin film, and not significantly affecting the bandgap of the thin film material itself. At the same time, the preparation method facilitates epitaxial growth on a IIIA group metal oxide substrate to form a single-layer or multi-layer structure, is simple and convenient to operate, has a low cost, and is suitable for large-scale preparation.

[0076] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0077] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0078] Furthermore, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a p-type IIIA group metal oxide semiconductor thin film, characterized in that: The p-type IIIA group metal oxide semiconductor film is obtained by using the MOCVD method, with a group IIIA metal source, an oxygen source, a group VIA non-oxygen precursor and a p-type doping precursor as raw materials for deposition reaction.

2. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to claim 1, characterized in that: The Group IIIA element in the Group IIIA metal source includes gallium and / or aluminum; Preferably, the Group IIIA metal source comprises an organometallic compound containing a Group IIIA element; Preferably, the organometallic compound containing a Group IIIA metal includes at least one of trimethylgallium, triethylgallium, trimethylaluminum or triethylaluminum.

3. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to claim 1 or 2, characterized in that: The oxygen source comprises at least one of oxygen, water or laughing gas; Preferably, the molar ratio of the oxygen element in the oxygen source to the Group IIIA element in the Group IIIA metal source is (100-500):

1.

4. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to any one of claims 1 to 3, characterized in that: The Group VIA element in the Group VIA non-oxygen precursor includes at least one of sulfur, selenium or tellurium; Preferably, the Group VIA non-oxygen precursor comprises an organic compound containing a Group VIA element; Preferably, the organic compound containing a Group VIA element comprises at least one of thiol, dimethyl sulfide, diethyl sulfide, selenol, dimethyl selenium, diethyl selenium, tellurol, dimethyl tellurium or diethyl tellurium; Preferably, the molar ratio of the Group IIIA element in the Group IIIA metal source to the Group VIA element in the Group VIA non-oxygen precursor is (3-30):

1.

5. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to any one of claims 1 to 4, characterized in that: The p-type doping precursor contains at least one of lithium, beryllium or magnesium as the doping element; Preferably, the p-type doping precursor comprises an organometallic compound containing a doping element; Preferably, the organometallic compound containing the doping element comprises at least one of lithium acetylacetonate, beryllium acetylacetonate, magnesium cyclopentadienyl or diethyl magnesium; Preferably, the molar ratio of the doping element in the p-type doping precursor to the group IIIA element in the group IIIA metal source is (0-10):1000.

6. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to any one of claims 1 to 5, characterized in that: The temperature of the deposition reaction is 500-1000°C; Preferably, the pressure of the deposition reaction is 30-100 mbar.

7. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to any one of claims 1 to 6, characterized in that: The deposition reaction is carried out on a substrate; Preferably, the material of the substrate comprises a Group IIIA metal oxide; Preferably, the Group IIIA metal oxide comprises at least one of gallium oxide, aluminum oxide or gallium aluminum oxide; Preferably, the Group IIIA metal oxide is n-doped.

8. The method for preparing a p-type IIIA group metal oxide semiconductor thin film according to any one of claims 1 to 7, characterized in that: After the deposition reaction is completed, annealing is performed to obtain the p-type IIIA group metal oxide semiconductor thin film; Preferably, the annealing temperature is 600-1200°C and the time is 0.5-5min; Preferably, the p-type Group IIIA metal oxide semiconductor film has a thickness of 50 nm to 10 μm.

9. A p-type IIIA group metal oxide semiconductor thin film, characterized in that: Obtained according to the preparation method according to any one of claims 1 to 8.

10. The p-type Group IIIA metal oxide semiconductor thin film according to claim 9, characterized in that: The carrier concentration of the p-type IIIA metal oxide semiconductor film is 1.0×10 13 ~5×10 20 cm -3 , the resistivity at -50℃ to 200℃ is ≤2500Ω·cm.

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